Systems and methods for forming a plurality of valleys on an inner circumferential surface of a cylinder liner for uniform oil film thickness are disclosed. In one aspect, an internal combustion engine includes a piston; and a cylinder liner surrounding the piston, wherein the cylinder liner has a plurality of valleys on an inner circumferential surface of the cylinder liner, and wherein the plurality of valleys are formed to a frequency of 7 to 14 valleys per millimeter (mm) having a depth of at least 1 micrometer (μm).

Systems and methods for forming a plurality of valleys on an inner circumferential surface of a cylinder liner for uniform oil film thickness are disclosed. In one aspect, an internal combustion engine includes a piston; and a cylinder liner surrounding the piston, wherein the cylinder liner has a plurality of valleys on an inner circumferential surface of the cylinder liner, and wherein the plurality of valleys are formed to a frequency of 7 to 14 valleys per millimeter (mm) having a depth of at least 1 micrometer (μm).

The invention relates to a honing machine and to a method for carrying out honing operations on orthogonally aligned bores in a workpiece, in particular for honing cylinder bores and a bearing race bore in a cylinder crankcase.

The invention relates to a honing machine and to a method for carrying out honing operations on orthogonally aligned bores in a workpiece, in particular for honing cylinder bores and a bearing race bore in a cylinder crankcase.

A honing tool includes a honing stone holder and a branching lubricant duct arranged in the honing stone holder. The branching lubricant duct has a straight section, first and second diagonal sections connected to and positioned diagonally to the straight section, and first and second transition sections that adjoin the first and second diagonal sections, respectively, and are arranged in a first plane parallel to and spaced from the straight section. The duct also has first and second open end sections continuing from the first and second transition sections, respectively, and directed towards a second plane arranged parallel to the first plane and in which the straight section is situated. In an example embodiment, the honing tool includes a honing stone fixed in the honing stone holder between the first and second transition sections.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A cylinder liner of the present invention is a cylinder liner mounted on a cylinder block and formed of flaky graphite cast iron, at least a nitrided layer is provided on an inner periphery of the cylinder liner, and a cross hatching section is formed on the inner periphery, a roughness curve of the inner periphery has a plateau honing shape, a ten-point average roughness Rz of the inner periphery pursuant to JIS B0601:1982 is 4.0 μm or less, and an average value of an area ratio of pits generated in the inner periphery is 8% or less.

A tool (1) for mechanochemical treatment comprises a shaft (10), a number n of working ledges (20), n≧1, and a force application arrangement (2). The force application arrangement (2) is configured for applying a working force (F) on the working ledges (20). The working ledges (20) comprises wear-resistant material with a Vickers number above 800 HV and a Young modulus above 200 GPa. Each working ledge (20) has a contact surface (22) facing away from a main axis (11) and having a surface roughness Ra below I μm. The contact surface (22) has a convex curvature which has a radius of curvature that is at most equal to a closest distance from that point to the main axis. A width of the contact surface (22) is less than r/2n. The working force applied on each working ledge (20) is at least P−L−r/2n, where P=107 Pa and L is the contact surface length.

A tool (1) for mechanochemical treatment comprises a shaft (10), a number n of working ledges (20), n≧1, and a force application arrangement (2). The force application arrangement (2) is configured for applying a working force (F) on the working ledges (20). The working ledges (20) comprises wear-resistant material with a Vickers number above 800 HV and a Young modulus above 200 GPa. Each working ledge (20) has a contact surface (22) facing away from a main axis (11) and having a surface roughness Ra below I μm. The contact surface (22) has a convex curvature which has a radius of curvature that is at most equal to a closest distance from that point to the main axis. A width of the contact surface (22) is less than r/2n. The working force applied on each working ledge (20) is at least P−L−r/2n, where P=107 Pa and L is the contact surface length.

A honing tool (100) for machining an inner face of a bore in a workpiece with the aid of at least one honing operation comprises a tool body (110) that defines a tool axis (112); a first cutting group (160-1), attached to the tool body, having a plurality of radially feedable first carriers (150-1) that are feedable radially with respect to the tool axis (112) by means of an associated first cutting group feeding system (170-1), wherein each first carrier covers, on its radial outer side, a circumferential angle range of at least 20° and carries, on its outer side (154), a single first cutting material body that is wide in the circumferential direction or a plurality of narrow first cutting material bodies (140-1), which are arranged in a manner spaced apart from one another; and a second cutting group (160-2), attached to the tool body, having a plurality of radially feedable second carriers (150-2) that are feedable radially with respect to the tool axis (112), independently of the first carriers (150-1), by means of an associated second cutting group feeding system (170-2), wherein each second carrier (150-2) carries, on its radial outer side (154), a single narrow second cutting material body (140-1, 140-2). All the cutting material bodies (140-1, 140-2) of the first and the second cutting group are arranged in an axially short cutting region (130) that has a length, measured in the axial direction, which is much less than an effective outside diameter of the cutting groups with the cutting material bodies fully retracted.